The present invention relates to a process for making generally decorative articles having a lens cap thereon and to the articles made by this process. More particularly, it relates to a process and article in which a fluent plastic composition is cast onto a controlled-flatness substrate so as to produce a decorative article which is free of optical distortions.
Trim strips of various configurations and decorative articles and emblems have been used in the automotive industry to decorate and protect automobile body surfaces, and other surfaces in the passenger compartment. In recent years, emphasis has been placed on the use of plastic trim strips which do not corrode and which can be adhesively attached to the automobile body without fasteners.
One such trim strip is shown in U.S. Pat. No. 4,446,179, issued May 1, 1984, to Waugh and assigned to the assignee of the present invention. Waugh discloses a decorative trim strip which may consist of an elongate decorative foil member having thereon an impact-resistant overlay having radiused edges and providing a lens effect to the foil member. An adhesive is used to bond the trim strip to the surface to be decorated. Another trim strip is shown in U.S. Pat. No. 4,560,596, issued December 24, 1985, to Coscia, and also assigned to the assignee of the present invention. Coscia discloses a trim strip which includes a foil member whose upper surface is provided with a decorative pattern. The upper surface is partially covered by a weather-resistant and impact-resistant plastic overlay having radiused edges and providing a lens effect to the foil member. The plastic overlay section of the foil member is essentially coextensive with the width of the automotive body component to be decorated. When the trim strip is applied to the body component, the uncovered end portions of the foil member are wrapped around the component. In the processes of Waugh and Coscia the substrate is held flat and horizontal, preferrably by vacuum hold-down, during casting and curing of the plastic overlay or lens cap.
Recently, interest has arisen in utilizing decorative articles to cover large, irregularly shaped surface areas and components on an automobile, previously, trim strips of the type shown in the Waugh and Coscia patents have been of a constant width and shape. This facilitates uniform casting of a fluent plastic composition onto the foil member prior to curing the composition to form the plastic overlay. When a decorative article which varies in width or shape is to be produced by casting a fluent plastic composition onto a substrate, ensuring that proper amounts of the composition are deposited on all portions of the substrate is important. One technique which has been used in the past to cast a fluent composition on a substrate in an irregular pattern is disclosed in U.S. Pat. No. 4,409,264, issued Oct. 11, 1983, to Gilleo et al, and U.S. Pat. No. 4,468,425, issued Aug. 28, 1984, to Gilleo et al. The Gilleo et al patents suggest that an irregularly shaped area defined by a pattern of a low surface energy compound, such as a fluorochemical, printed on the substrate surface, can receive a quantity of a liquid resin. The substrate is then wobbled or tipped in various directions, causing the liquid resin to flow over the irregularly shaped area to the area boundaries. While this may be an acceptable technique to use with some area shapes, it is not effective when the area to be covered withg a fluent composition is significantly elongated.
Copending application Ser. No. 025,349, filed Mar. 13, 1987 provides for an improved process for making a decorative article in which an elongated substrate area of varying width or shape is cast with a fluent plastic composition and cured to form a clear plastic lens cap. As with the Waugh and Coscia processes discussed above, the substrate is held substantially flat and horizontal, preferrably by vacuum hold-down, during the casting and curing process.
However, it has been found that in some instances optical distortions occur in the decorative articles produced by such processes. The optical distortions, which can be described as an "orange peel" appearance, occur primarily in large area decorative trim strips having elongated areas of varying width or shape which are conformed to an automobile body component such as the verticle pillars located just to the rear of the front doors of many passenger automobiles.
Such pillars are known in the industry as "B-pillars" and "C-pillars". It has become fashionable for the covering, paint, or coating on B-pillars and C-pillars to have a smooth glass-like luster. The use of decorative articles having a lens cap as described in Waugh, Coscia and copending application Ser. No. 025,349, are particularly well suited as a covering for B-pillars and C-pillars because of the lens effect which optically enhances the surface beneath the lens cap. But, this is only true to the extent that there are no optical distortions in that covering.
Accordingly, the need exists for an improved process for making a decorative article in which a controlled-flatness substrate is cast with a fluent plastic composition to produce an elongate decorative article which is free of optical distortions.